Safety device



.June 8, 11943,

H. HACKLANDER 2,321,380 SAFETY DEVICE vFiled Jan.v 17 1942 2 sheets-sheet 1 I 19 I A M el 20 Jwewfoi Hcm HUC/(Lander June s, 1943. H. HACKLANDR v2,321,380

SAFETY DEVICE Filed Jan. 17, 1942 2 Sheets-Sheet 2 gnwc/wto H cm Hao/Mander* Patented June 8, 1943 SAFETY DEVICE Hans Hackiandcr, Linden, N. J., assigner to The Singer Manufacturing Company, IElizabeth, N. .1., .a corporation of New Jersey Application January 1'?, 1942, Serial No. 427,099

(Cl. 192l.29)

10 Claims.

This invention relates to safety devices for machines which are controlled by an operator and particularly to devices adapted to preventl the repetition of the machine cycle in the event the operator inadvertently maintains the control treadle depressed.

This invention is particularly designed for use with sewing machines of the class adapted to produce detached groups of stitches and in which means are employed for automatically stopping the machines at the completion of each stitch group.

The primary object of this invention is to provide a simple and inexpensive safety device for controlling the stop-motion lever of a sewing machine, so that after the machine has been started by actuation of the usual stop -motion-controlling a treadle device, its automatic stopping is insured due to the action of the safety device which renders the treadle device ineifective until the termination of the stitching cycle.

With the above and other objects in view, as will hereinafter appear, the invention comprises the devices, combinations and arrangements of parts hereinafter set forth and illustrated in y vthe accompanying drawings of a preferred embodiment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

The several features of the presentinvention will be clearly understood from the following description and accompanying drawings in which:

Fig. 1 is a side elevation of a sewing machine and its supporting table having the present invention embodied therein.

Fig. 2 is a perspective view of ra connecting rock-shaft which is shown in broken lines in Fig. 1.

Fig. 3 is a side view of the safety device illustrated in starting position.

Fig. 4 is a side view of the safety device illustrating in full lines the relative positions of its component parts when the treadle mechanism is fully depressed, and illustrating in broken lines the relative positions of the parts the moment before the latching means is opened.

Fig. 5 is a disassembled perspective view of the major parts of the safety device.

Referring to the drawings I0 represents the legs of a table top which supports a sewing machine having the cylinder-bed or work-arm |2 from the rear end of which rises the standard I3 from which laterally extends the hollow overhanging arm I4 terminating in the head I5. Journaled within and longitudinally of the arm I4 is the main-shaft I6 from which is derived, through the usual operative connections, the reciprocating movements of the needle-bar I1 carrying the needle I8.

The stop-motion mechanism of the present machine is susbtantially the same as that of the United States patent to W. L. Barron, No. 1,093,-

241, of April 14, 1914. Upon the rearward end portion of the main-shaft I6 are mounted the usual fast and loose pulleys I9 and 2|). stopping-cam 2| is also mounted upon and adapted to rotate with the shaft I6. Cooperating with the stopping-cam 2| is the plunger-bar 22 mounted within the swinging stop-lever 23 fulcrumed at 26 upon a bracket 25 of the standard I3. The lever 23 carries the belt-shipper arm 26. Mounted upon the pivotal pin 21 of the bracket 28 is the angular shift-lever or operative means 29 for tilting the stop-lever 23 in opposition to its spring 30 to shift the driving belt, not herein shown, from the loose pulley to the tight pulley |9 and disengage the plunger-bar 22 from the stopping cam 2|. c

The stop-lever 23 is detained in running position by the usual latch means not shown herein and this means is adapted to thus retain the stop-lever in running position until the stitching cycle is terminated at which time the stop-lever is released and, under the pressure of the spring 3i), springs outwardly to engage the plunger-bar 22 with the stopping-cam 2|, all in the usual manner.

It may therefore be understood that when the treadle-actuated chain 3|, one end of which is connected directly to the lever 29, is moved downwardly, the stop-lever 23 is swung inwardly thereby throwing the machine into operation. As hereinabove noted, the stop-lever 23 is held latched in this position until it is automatically released at the end of the stitching cycle.

In high speed machines of the present type which is adapted for producing groups of tacking stitches and the like, only a few seconds elapse between the starting of the machine and the completion of one stitch-group. It frequently happens that the operator by continuing to hold the treadle or manipulative means depressed, prevents the spring or the like from promptly moving the stop-motion lever 23 into stopping position, thereby resulting in defective work, or in 'the breakage of machine parts. The use of the present safety device obviates this difficulty.

Mounted between the table legs I0 is a cross member 32 supporting a treadle 33 which is pivotally mounted at point 34 upon a bracket 35 fixed to the cross-member. The upper end of the manipulative means 33 has the lower end of a chain 34 secured thereto; the upper end of the chain being secured to the head portion 35 of one of the arms 36 of the safety device. The lower end cf the first mentioned chain 3| is secured to a turnbuckle 31 which is also connected vto a chain 38 the lower end of which is fastened tothe crank 39, Fig. ,2, carried by the rock-shaft 4B.

.The

This rock-shaft 40 is suitably mounted beneath the table top Il and a second crank 4I carried by the rock-shaft has the upper end of a chain 42 secured thereto. The lower end of the chain 42 is made fast to the head end 43 of a second arm 44 of the safety device.

The safety device is preferably constructed of sheet metal and comprises a base member 45 which is secured by means of screws 46 to a block 41 suitably supported upon the oor. Struck up from the base member 45 are the fulcrum ears 48 provided with the oppositely aligned apertures 49 which are adapted to receive the cross-pin 59. Pivotally mounted upon the cross-pin D is the arm 44 which is of inverted U-shaped section and which is provided with a pair of oppositely aligned cross-pin-receiving apertures one of which is indicated by the number 5|. Slidably mounted within the arm 44 and pivotally and shiftably mounted upon the cross-pin 59 is a second arm member 36 which is provided at one end with the elongated crosspin-receiving aperture 52. 'Ihe nut 53 locks the cross-pin 59 in position and the washers 54, which are mounted upon the cross-pin and disposed adjacent to the outer faces of the arm 44, permit the arm 44 to swing readily about the cross-pin.

Formed in the head 35 of the arm 36 is a notch 55 which is adapted to receive the head portion 43 of the arm 44 thereby to lock the two arms together. As may be best seen in Fig. 3, a tension spring 56, one end of which is secured to a linger 51 struck up from the base member 45, and the other end of which is secured to a finger 58 depending from the arm 36, causes the notch to forceably engage the head 43 of the arm 44; the aperture 52 permitting the arm 36 to shift longitudinally of itself. Thus it will be understood that the notched head 35 and the spring 56 form a latching mechanism.

Projecting upwardly from the base member 45 is a linger 59 which is adapted to be engaged by the depending portion 60 of the head 35 and, due to the inclined edge 60 of this depending portion, the linger 59 forces the arm 36 to shift longitudinally of itself whenever this arm 36 is swung downwardly under the action of the manipulating means 33. As may be seen in Fig. 4, as soon as the ringer 59 engages the inclined edge 60 of the head 35, the arm `36 begins to shift endwise and when the arm 36 reaches a predetermined point in its arcuate movement, as illustrated by broken lines in Fig. 4, the head 43 is made free of the latchingmechanism and it is at liberty to spring upwardly under the action of the stop-motion spring 39. erator releases the manipulating means 33 the arm 36 swings upwardly to assume its normal or starting pcsition under the action of a tension spring 6l the lower end of which is secured to the head 35 and the upper end` of which is secured to the chain 42. Upon reaching this start When the oping position the notch 55 again engages the head 43 under the forces of springs 56 and 6|. It is to be understood, therefore, that whenever the operator depresses the manipulative means 33, the chain 34 pulls the arm 36 about its pivotal axis 59, and this arm 36, being'in engagement with the arm 44, actuates the chain 42 and consequently the operative means 29 to thus start the sewing machine. Before the manipulative means reaches the end of its stroke the head 35 engages the finger V59 which forces the arm 36 to shift lengthwise of itself and thus to open the latching mechanism and to release the operative means 29. If the operator then inadvertently maintains the manipulative means depressed, the machine cannot repeat its cycle of operation. Upon the release of the manipulative means the safety device is again ready to initiate the starting of the sewing machine cycle.

The end portion of arm 44 adjacent to the cross-pin 59 is provided with a regulating screw 62 which is threaded therein. The lower end of this regulating screw engages the base member 45 for the purpose of regulating the stroke oi the arms 36 and 44. Provided on the screw is a lock-nut 63 which is adapted to bear against the top portion of the arm 44 thereby to lock the screw in any regulated position. It is to be understood that as the regulating screw 62 is advanced within the arm 44 the stroke of the arms 36 and 44 become shorter.

From the above description it is to be seen that by constructing the present safety device of sheet metal a most simple, compact and economical device results. In fact the device comprises merely three specially formed sheet metal parts which require only the addition of several common commercial elements to complete the device. Due to its simplicity and ruggedness of construction, the present device is particularly suited for the rigorous use to which such devices are subjected.

Having thus set forth the nature of the` invention what I claim herein is:

1. A safety device adapted to be used with a machine of the class described having operative mechanism and manipulative means for initiating the action of said operative mechanism, said safety device comprising, a stationary base member, iirst arm pivotally mounted upon said base member, one end of said rst arm adapted to be connected to said operative mechanism, a second arm pivotally mounted upon said base member, one end of said second arm adapted to be connected to and moved by said manipulative means, spring actuated latching means for locking said rst arm and said second arm together in starting position, and means to open said latching means at a predetermined period during the movement of said second arm.

2. A safety device adapted to be used with a machine of the class described having operative mechanism and manipulative means for initiating the action of said operative mechanism, said safety device comprising, a stationary fulcrum member, a rst arm pivotally mounted. upon said fulcrum member, one end of said first arm adapted to be connected to said operative mechanism, a second arm pivotally mounted upon said fulcrum member, one end of said second arm adapted to be connected to and moved by said manipulative means, spring actuatedr latching means for locking said first arm and said second arm together in starting position, and means to open said latching means at a predetermined period duringthe movement of said second arm.

3. A safety device adapted to be used with a machine of the class described having operative mechanism and manipulative means for initiating the action of said operative mechanism, said safety device comprising a fulcrum member, a first arm pivotally mounted upon said fulcrum member, one end of said rst arm adapted to be connected to said operative mechanism, a, second arm pivotally and shiftably mounted upon said fulcrum member, one end of said second arm adapted to be connected to said manipulative means and to be moved thereby, spring actuated latching means for locking said first arm and said second arm together in starting position, and means to shift said second arm lengthwise of itself to open said latching means at a predetermined period during the movement of said second arm.

4. A safety device adapted to be used with a machine of the class described having operative mechanism and manipulative means for initiating the action of said operative mechanism, said safety device comprising, a base member, a first arm pivotally mounted upon said base member, said iirst arm having a head end adapted to be connected to said operative mechanism, a second arm pivotally and shiftab-ly mounted upon said base member, said second arm having a head end adapted to be connected to said manipulative means and to be moved thereby, spring actuated latching means associated with the 1'' head end of said second arm for locking the head end of said rst arm and the head end of said second arm together in starting position, and means to shift said second arm lengthwise of itself to open said latching means at a prede- 7 termined period during the movement of said second arm.

5. A safety device adapted to be used with a machine of the class described having operative mechanism and manipulative means for initiating the action of said operative mechanism, said safety device comprising, a fulcrum member, a first arm pivotally mounted upon said fulcrum member, a second arm pivotally and shiftably l mounted upon said fulcrum member, one end of one of said arms adapted to be connected to said operative mechanism and one end of the other of said arms adapted to be connected to and moved by said manipulative means, spring actuated latching means for locking said first arm and said second arm together in starting position, and means to shift lengthwise of itself that arm which is pivotally and shiftably mounted upon the fulcrum member, said last noted arm being shifted for the purpose of opening said latching means at a predetermined period during the movement of that arm which is connected to said manipulative means.

6. A safety device adapted to be used with a machine of the class described having operative mechanism and manipulative means for initiating the action of said operative mechanism, said safety device comprising, a fulcrum member, a hollow arm, a second arm normally disposed within said hollow arm, one of said arms being pivotally mounted and the other being pivotally and shiftably mounted upon said fulcrum member, said hollow arm having a head end adapted to be connected to said operative mechanism, said second arm having a head end adapted to be connected to and moved by said manipulative means, a spring actuated latching means for locking together in starting position the hands of said hollow arm and said second arm, and means for shifting lengthwise of itself that arm which is pivotally and shiftably mounted upon said fulcrum member to open said latching means at a predetermined period during the movement of said second arm.

'7. A safety device of the class described comprising, a base-member, a fulcrum member carried by said base member, two normally parallel arms pivotally and coaxially mounted upon said fulcrum member, said arms being adapted to be moved arcuately about said fulcrum member, latching means carried upon one of said arms for locking both arms together, spring means, one of said arms being shiftable lengthwise of itself in opposition to said spring means to release said latching means, and means carried by said base member for engaging said shiftable arm at a predetermined period during the arcuate movements of said arms thereby to shift the same lengthwise of itself.

8. A safety device adapted to be used with a machine of the class described having operative mechanism and manipulative means for initiating the action of said operative mechanism, said safety device comprising, a fulcrum member, tWo normally parallel arms pivotally and coaxially mounted upon said fulcrum member, two adjacent end portions of said arms being adapted to be respectively connected to said operative mechanism and said manipulative means, latching means associated With said adjacent end portions of the arms for normally locking said arms together in starting position, said arms being adapted to be moved by said manipulative means in a path about said fulcrum member, means to open said latching means at a predetermined period during the movements of said arm, and spring means to reengage said latching means with said arms.

9. A safety device adapted to be used with a machine of the class described having operative mechanism and manipulative means for initiating the action of said operative mechanism, said safety device comprising, a stationary base member, a first arm pivotally mounted upon said base member, said rst arm having a head end adapted to be connected to said operative mechanism, a second arm pivotally and shiftably mounted upon said base member, said second arm having a head end adapted to be connected to and moved by said manipulative means, the head end of said second arm having a notch formed therein normally engaged by the head end of said first arm, spring means carried by said base member and engaging said second arm, means carried by said base member for engaging the head end of said second arm at a predetermined period during the movement thereof to shift the same lengthwise of itself in opposition to said spring means for disengaging the head ends of said arms, and a second spring means connected to the head end of said second arm and adapted to be connected to said operative means for cooperating with said first mentioned spring means in reengaging said head ends.

10. A safety device of the class described including, three unitary sheet-metal elements, one of said sheet-metal elements comprising -a base member, the remaining sheet-metal elements comprising a pair of substantially parallel vibratory members fulcrumed upon said base member, said vibratory members adapted t0 be locked together during `a portion of their vibratory movement, and means for separating said vibratory members at a predetermined point in their movement so that said vibratory members may act independently of each other during the remainder of their vibratory movement.

' HANS HACKLANDER. 

